Conventionally, such saws employ steel blades formed with integral teeth which are ground and set according to particular requirements. Such blades require sharpening from time to time and are not suitable for some manufactured materials of which chip-board is an example.
It has been proposed to use teeth of a hard material, for example tungsten carbide, mounted on a circular blade carrier but the mounting techniques employed do not provide a sufficient degree of security for other forms of carrier, particularly those where linear reciprocation is required. Furthermore, it is known to mount teeth in circular saw blades by use of a keyway. Different styles of keyway are disclosed in GB-A-275554, GB-A-1464640, US-A-3945289 and EP-A-0117991. Another style of keyway for a reciprocatable blade is disclosed in GB-A-665433. However, in all these known constructions, it is a difficult task to hold the teeth in position during manufacture of the blades.
Moreover, some of the tooth configurations previously adopted have been such that tooth production by powder moulding and sintering techniques has been difficult because of abrupt and large changes in the cross-sectional area of the tooth.